various methods have been utilized to target a pharmaceutical agent to a specific tissue or anatomic area in need of treatment. Most commonly the active agent is administered directly to the treatment site, for example, by injection. Such targeted delivery is desirable where the area in need of treatment is localized or where systemic delivery may result in toxicity. In treating diseases and lesions of the skin and surrounding tissues, active agents are often administered topically.
Diverse substances have been used in conjunction with topically applied active agents to increase the delivery of the active agent across the barrier of the skin. The delivery of active chemotherapeutic agents across the skin has been modified by simultaneous topical use of penetration enhancing agents such as Azone (1-dodecylazacycloheptane-2-one) or 1-[2-(decylthio)ethyl]azacyclopentane-2-one (HPE-101). Uekama et al., J. Pharm. Pharmacol. 44:119-121 (1992). Parab U.S. Pat. No. 5,087,620 describes compositions for topical use containing asteroid as the active agent and imidazole or imidazole derivatives as penetration enhancers. Other penetration enhancers include surfactants such as sodium lauryl sulfate.
Sage et al. U.S. Pat. No. 5,334,138 describes the co-iontophoresis of a vasoconstrictor and an active agent, where the vasoconstrictor acts to enhance the iontophoretic delivery of the active agent. Sage et al. U.S. Pat. No. 5,302,172 describes the co-iontophoresis of an active agent and a vasodilator, where the vasodilator acts to increase the amount of active agent delivered iontophoretically.
Other methods have been designed to target a systemically delivered agent to a particular treatment site. Radiolabelled monoclonal antibodies have been used to target radiation therapy to various tumor types, while whole body hyperthermia has been proposed as a means of targeting systemic platinum therapy to specific tissue types (Riviere et al., Cancer Research 50:2075-2080 (1990).